A California woman said anti-vaxxers endangered her baby’s life and forced the 6-month-old girl into a month-long quarantine.

Jennifer Simon took her daughter, Livia, to the doctor Jan. 2 because she had a cold, and the pediatrician’s office called two days later to report that an unvaccinated child with measles had been there the same day.

Measles – one of the most contagious diseases on Earth – can linger in the air or on surfaces for hours, and children who contract the disease can become deaf or even die.